1. Field of the Invention
The present invention relates to a method for manufacturing sharp spine-shaped projections on ceramic. More specifically, the present invention is a kind of methods for decorating ceramics in ceramics manufacturing, and relates to a method for forming a group of sharp spine-shaped projections on outside of ceramics.
2. Description of Related Art
Ceramics generally have been made by elutriating, kneading, forming, decorating, first burning, glaze applying, and second burning.
The elutriating step is a step of pulverizing clay finely, wetting the pulverized clay, sifting the wet clay to remove the contaminants, taking settled clay, and drying settled clay in the shade, and the kneading step is a step of adding proper amount of water into the dried clay and kneading the mixture by hands or a rice-cake mallet. By well kneading, clay can be soft, air can be removed, and it prevents ceramics expanding and breaking during the burning steps.
The forming step is a step of forming a shape of ceramic, and it can be done with a Potter's wheel or a mould. In a Potter's wheeling, the base is made by drying the formed ceramic for about a day and cutting the lower part of the ceramic.
The decorating step is a step of decorating the formed, but not yet fully dried ceramic with various patterns on outside of the ceramic, and there are known, various decorating methods. For example, seven decorating methods for a grayish-blue-powdered celadon have been known as inlaying, printing, thin papering, engraving, carving, paint brushing, and dipping.
The first burning step is a step of burning the ceramic at 850˜900° C. first for the purpose of full-drying the ceramic, removing the contaminants in the clay and helping glazing.
The glaze applying step is a step of applying a glaze to the first burnt ceramic, and there are dipping, spraying, pouring and so on. A glaze is a kind of glass layer giving a beautiful gloss to the ceramic and preventing water passing through.
The second burning step is a step of burning the glazed ceramic at 1200˜1300° C., letting the glaze fused to the ceramic, and decorating the ceramic beautifully by the glaze.
Kilns for burning can be various such as firewood kilns, gas kilns, oil kilns, and electric kilns. For burning methods, there are an oxidative burning that burns fuel completely with enough oxygen and a reduction burning that burns fuel incompletely by blocking the oxygen supply.
Meanwhile, changing conditions of the times have expected ceramics to be from simple ‘art crafts’ to ‘industry applicable products’ having a sense of beauty more and more.
To meet the expectancy and satisfy various customers' desire, new ceramic manufacturing technologies have been developed in a steady stream. For example, Korean Patent Publication No. 10-2002-0011831 disclosed the method of forming projection patterns on the craft by manipulating the mixing ratios of soils and glazes, and kiln temperature on second burning, and letting the glaze layer change on the ceramic surface. Korean Patent No. 10-480370 disclosed a manufacturing method ceramic tea-things having projections for the finger-pressure with sharp ends by making irregular engravings of under 5 mm diameter on the whole surface of the ceramic, applying porridge-like decorating material made of white clay onto the surface of the engravings with a brush, letting the engravings filled with the decorating material and forming projections for finger-pressure with sharp ends.
However, the former technology has the problem that projections are very small and shapes of projections are not various. So, it is difficult to get desired various patterns. The latter technology has a finger-pressure effect. However, it reduces a sense of beauty and customers' desire to buy.